Data definition apparatus, systems, and methods

ABSTRACT

An apparatus and a system, as well as a method and article, may operate to send a selected data type without self-definition information to a receiver if a state capable of interpreting the selected data type has been maintained by the receiver, and to send the selected data type with the self-definition information to the receiver if the state capable of interpreting the selected data type has not been maintained by the receiver.

This application is a continuation of U.S. patent application Ser. No.12/473,424, filed on May 28, 2009, which is a continuation of U.S.patent application Ser. No. 10/736,052, filed on Dec. 15, 2003, nowissued as U.S. Pat. No. 7,583,694, which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

Various embodiments described herein relate to data processinggenerally, such as apparatus, systems, and methods used to transmit andreceive information, including data frames and packets.

BACKGROUND INFORMATION

Some communications protocols may use adaptive modulation (also known asadaptive bit loading), wherein the modulation type can vary bysub-carrier. This may occur, for example, with respect to communicationsusing the sub-carriers in various orthogonal frequency-divisionmultiplexing (OFDM) systems. Thus, when adaptively modulated data, whichmay include packets, is sent to a receiver, a question may arise: Shouldthe modulation used in conjunction with the communication be indicatedas well (e.g., should the data be self-defined), or should the data besent without indicating the modulation type (e.g., should the data benon-self-defined)? Transmitting self-defined data may incur greateron-air overhead. On the other hand, sending non-self-defined data mayrequire several assumptions about the receiver state.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an apparatus and a system according tovarious embodiments;

FIG. 2 is a diagram including self-defined and non-self-defined dataaccording to various embodiments;

FIG. 3 is a flow chart illustrating several methods according to variousembodiments; and

FIG. 4 is a block diagram of an article according to variousembodiments.

DETAILED DESCRIPTION

During the process of communicating information, wireless devices mayoperate to optimize communications to a wireless channel using atraining process, followed by the exchange of frames, all or some ofwhich may be trained to that particular channel (for example, usingadaptive modulation or bit loading). The trained frames may beself-defined, such that they can be received without any particularstate being maintained by the receiver. The trained frames may also benon-self-defined, such that a receiver may use a state retained from aprior training exchange to receive and properly interpret them.

In various embodiments, a transmitter may select between self-definedand non-self-defined communications according to whether there is reasonto believe that the necessary state for reception has been retained atthe receiver. Many factors may lead to such belief. For example, thetransmitter may determine that:

-   -   The transmitter is the only device within a reception range of        the receiver.    -   The receiver and transmitter are the only extant devices having        a particular network code, and training depends on a matching        network code.    -   No other transmitters will attempt a training exchange with the        receiver, and training depends on a device address.    -   There has been no opportunity for any other device to        communicate with the intended receiver since a training exchange        with the transmitter.

For example, in communications using a protocol based on the Instituteof Electrical and Electronics Engineers (IEEE) 802.11 protocol, areceiving station may perform training through the exchange of frameswith a transmitting station (e.g. a peer-to-peer communication usingRTS/CTS with additional training feedback). If it can be determined thatthis training session is followed by an exchange of trained frameswithout any opportunity for a third party to gain access to thecommunications medium or channel, the trained frames may be sent in anon-self-defined format. Thus, in some embodiments using a version ofthe IEEE 802.11 protocol (e.g., using an RTS/CTS/DATA/DATA/DATA/BlockAck scheme in which each frame is separated by a short gap), no otherdevice may be permitted access to the receiver via the communicationsmedium, except the original training transmitting station, and the datato be communicated may be sent in non-self-defined format. For moreinformation on the various IEEE 802.11 standards, please refer to “IEEEStandards for Information Technology—Telecommunications and InformationExchange between Systems—Local and Metropolitan Area Network—SpecificRequirements—Part 11: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY), ISO/IEC 8802-11: 1999” and related versions.

If, however, control of the medium or channel has been yielded toanother device after training occurs, then the transmitting station maydetermine that the state of the receiving station has not beenmaintained, and any trained frames sent to the receiver thereaftershould be sent in a self-defined format. For example, this may happenwhen the adaptation is updated during a DATA/Ack (with training)exchange followed by a CSMA/CA (Carrier Sense Multiple Access withCollision Avoidance) contention, such that control of the communicationschannel is lost during a pause that occurs before the next trainingrequest. Self-definition information may be sent separately from theassociated data, or in close conjunction with the communication, as apart of a packet header for the associated data, for example.

For the purposes of this document, the term “data type” includes anytype of communication and/or data associated with a formattingmechanism, such as a multicarrier transmission technique (e.g.,orthogonal frequency division multiplexing, or OFDM), a modulation, acode rate or type, such as a forward error correction (FEC) code rateand/or type, the knowledge of which is typically required to decode andinterpret the data. A selected data type may be data that iscommunicated with or without an indication of the formatting mechanism,such that the data is self-defined when an indication of the formattingmechanism is transmitted with the data, and non-self-defined when anindication of the formatting mechanism (e.g., self-definitioninformation) is not transmitted with the data.

For the purposes of this document, “self-defined” or “self-definition”information or data may include an indication, in conjunction withspecific information or data, of a formatting mechanism, such as amulticarrier transmission technique, a modulation type, a code rateand/or type, a power, and/or a beam-forming parameter, perhaps for usewith one or more sub-carriers and/or a multiple-input, multiple-output(MIMO) communications system (wherein multiple antennas and coding canbe used to communicate via defined spatial channels, antenna diversity,space-time coding, beam-forming, and/or singular value decomposition(SVD) methods, known to those of skill in the art). A “state” maintainedby a receiver may mean any information retained by a receiver as aresult of a training exchange with a transmitter. The term “transceiver”(e.g., a device including a transmitter and a receiver) may be used inplace of either “transmitter” or “receiver” throughout this document.

FIG. 1 is a block diagram of an apparatus 100 and a system 110 accordingto various embodiments, each of which may operate in the mannerdescribed above. For example, an apparatus 100 may comprise atransmitter 114 to selectively send a selected data type 118 to areceiver 122 with or without self-definition information 126. Theapparatus 100 may also include a determination module 130 to determinewhether a state 134 capable of interpreting the selected data type 118has been maintained by the receiver 122 after the receiver 122 has beentrained to enter the state 134 by the transmitter 114.

The apparatus 100 may also include a memory 138 to store theself-definition information 126. As noted above, the self-definitioninformation 126 may indicate one or more of a multicarrier transmissiontechnique, a modulation, a code rate and/or type, a code, a power, and abeam-forming parameter. The selected data type 118 may be sent to thereceiver 122 by the transmitter 114 as a series of frames or packets,including a series of adaptively modulated packets, as well as in otherformats.

In another embodiment, a system 110 may comprise an apparatus 100 asdescribed above, as well as a receiver 122 to receive the selected datatype 118. The system 110 may further include an antenna 142, such as apatch, omnidirectional, monopole, or dipole antenna capable of beingcoupled to the receiver. A memory 146 may be included in the receiver122 to store an indication S of the state 134.

In summary, various embodiments may operate to send data 118 from atransmitter 114 to a receiver 122 using a communications medium, such asa carrier wave 150 and/or a physical connection 154 (e.g., wire,fiber-optics, and others). The data 118 may be sent with self-definitioninformation 126, or not, depending on whether a determination has beenmade as to whether a particular state 134 has been maintained by thereceiver 122. The state 134 may come into existence as a result of anevent, such as a training exchange between the transmitter 114 and thereceiver 122, as well as via other mechanisms discussed above.

FIG. 2 is a diagram including self-defined and non-self-defined dataaccording to various embodiments. Referring now to FIGS. 1 and 2, and asnoted previously, it can be seen that a state 134 retained by thereceiver 122 may come into existence as a result of an event 258, suchas a training exchange between a transmitter 114 and a receiver. Thus,after time t₀, when the event 258 has occurred, a selected data type118, 218, perhaps in a packet format, may be sent to the receiver 122without self-definition information 126, 226. However, after the passageof times t₁ and t₂, or whenever it is determined that the state 134 ofthe receiver 122 (sufficient to receive and properly interpret theselected data type 118, 218) has not been maintained, the selected datatype 118, 218 may be sent with self-definition information 126, 226.

The apparatus 100, system 110, transmitter 114, selected data type 118,218, receiver 122, self-definition information 126, 226, determinationmodule 130, state 134, memories 138, 146, antenna 142, carrier wave 150,physical connection 154, event 258, and indication S of the state 134may all be characterized as “modules” herein. Such modules may includehardware circuitry, and/or one or more processors and/or memorycircuits, software program modules, including objects and collections ofobjects, and/or firmware, and combinations thereof, as desired by thearchitect of the apparatus 100 and the system 110, and as appropriatefor particular implementations of various embodiments.

It should also be understood that the apparatus and systems of variousembodiments can be used in applications other than transmitters andreceivers, and other than for wireless systems, and thus, variousembodiments are not to be so limited. The illustrations of an apparatus100 and a system 110 are intended to provide a general understanding ofthe structure of various embodiments, and they are not intended to serveas a complete description of all the elements and features of apparatusand systems that might make use of the structures described herein.

Applications that may include the novel apparatus and systems of variousembodiments include electronic circuitry used in high-speed computers,communication and signal processing circuitry, modems, processormodules, embedded processors, data switches, and application-specificmodules, including multilayer, multi-chip modules. Such apparatus andsystems may further be included as sub-components within a variety ofelectronic systems, such as televisions, cellular telephones, personalcomputers, personal digital assistants (PDAs), workstations, radios,video players, vehicles, and others.

FIG. 3 is a flow chart illustrating several methods according to variousembodiments. A method 311 may (optionally) begin with training areceiver to enter a state capable of interpreting a selected data typeat block 321. The method 311 may include determining whether a statecapable of interpreting a selected data type has been maintained by thereceiver at block 331.

If it is determined that the desired state has been maintained by thereceiver at block 341, then the method 311 may include sending theselected data type without self-definition information to the receiverat block 351. If it is determined that the state has not been maintainedby the receiver at block 341, then the method 311 may include sendingthe selected data type with the self-definition information to thereceiver at block 361. In either case, the method 311 may then continuewith determining whether new and/or additional training should beperformed at block 371, perhaps on the basis of a selected amount oftime passing since training was last performed, and/or other factors. Iftraining is to be performed, the method 311 may continue with trainingthe receiver at block 321. If training is not needed, as determined atblock 371, then the method 311 may continue with determining, perhaps ata selected future time, whether the state has been maintained by thereceiver at block 331.

There are numerous ways in which a determination can be made as towhether the state capable of interpreting the selected data type hasbeen maintained by the receiver. For example, determining whether thestate has been maintained by the receiver may include determining thatthe receiver has not received a communication from another transmitterafter being trained to enter the state by the training transmitter. Inanother case, determining whether the state has been maintained by thereceiver may include determining that no transmitter (or other device)other than the training transmitter is capable of communicating with thereceiver. Still further, determining whether the state has beenmaintained by the receiver may include determining whether atransmission of information from a transmitter (or other device) otherthan the training transmitter has been directed to the receiver.

Other ways to determine whether the state has been maintained by thereceiver are possible. For example, determining whether the state hasbeen maintained by the receiver may include determining that thereceiver is operating in accordance with a protocol that prohibitscommunication with a transmitter (or other device) other than thetraining transmitter. In some embodiments, the protocol may prohibitreception from any other device by the receiver until the trainingtransmitter indicates that a communication session between the trainingtransmitter and the receiver is terminated. In some embodiments, theprotocol may be an Institute of Electrical and Electronics Engineers(IEEE) 802.11 protocol.

Still other mechanisms for determining whether the state has beenmaintained by the receiver may be used. For example, determining whetherthe state has been maintained by the receiver may include determining,by an access point, that no information will be communicated to thereceiver except by the access point. Determining whether the state hasbeen maintained by the receiver may also include determining thatcontrol of a communications channel in use by the receiver and thetraining transmitter has not been released by the training transmitter.

As noted previously, the self-definition information may be included inframes (e.g., byte-oriented framing, bit-oriented framing, and/orclock-based framing) and/or packets (e.g., a unit of data transmittedacross a packet-switched network), including in a packet header. Theself-definition information may indicate one or more of a multicarriertransmission technique, a modulation, a code rate or type, a power, anda beam-forming parameter.

It should be noted that the methods described herein do not have to beexecuted in the order described, or in any particular order. Moreover,various activities described with respect to the methods identifiedherein can be executed in serial or parallel fashion. For the purposesof this document, the terms “information” and “data” may be usedinterchangeably. Information, including parameters, commands, operands,and other data, can be sent and received in the form of one or morecarrier waves.

Upon reading and comprehending the content of this disclosure, one ofordinary skill in the art will understand the manner in which a softwareprogram can be launched from a computer-readable medium in acomputer-based system to execute the functions defined in the softwareprogram. One of ordinary skill in the art will further understand thevarious programming languages that may be employed to create one or moresoftware programs designed to implement and perform the methodsdisclosed herein. The programs may be structured in an object-orientatedformat using an object-oriented language such as Java, Smalltalk, orC++. Alternatively, the programs can be structured in aprocedure-orientated format using a procedural language, such asassembly or C. The software components may communicate using any of anumber of mechanisms well-known to those skilled in the art, such asapplication program interfaces or inter-process communicationtechniques, including remote procedure calls. The teachings of variousembodiments are not limited to any particular programming language orenvironment, including Hypertext Markup Language (HTML) and ExtensibleMarkup Language (XML). Thus, other embodiments may be realized, as shownin FIG. 4.

FIG. 4 is a block diagram of an article 485 according to variousembodiments, such as a computer, a memory system, a magnetic or opticaldisk, some other storage device, and/or any type of electronic device orsystem. The article 485 may comprise a processor 487 coupled to amachine-accessible medium such as a memory 489 (e.g., a memory includingan electrical, optical, or electromagnetic conductor) having associatedinformation 491 (e.g., computer program instructions, and/or otherdata), which when accessed, results in a machine (e.g., the processor487) performing such actions as sending a selected data type withoutself-definition information to a receiver if a state capable ofinterpreting the selected data type has been maintained by the receiver,and sending the selected data type with the self-definition informationto the receiver if the state capable of interpreting the selected datatype has not been maintained by the receiver.

Other actions may include determining whether the state capable ofinterpreting the selected data type has been maintained by the receiver.As noted above, determining whether the state has been maintained by thereceiver may include determining, by an access point, that noinformation will be communicated to the receiver except by the accesspoint, as well as determining that control of a communications channelused by the receiver and a training transmitter has not been released bythe training transmitter.

Implementing the apparatus, systems, and methods described herein mayresult in reducing the overhead used to transmit self-definitioninformation in conjunction with data for a variety of communicationsystems. This may in turn provide improved bandwidth utilization andreduced communication costs.

The accompanying drawings that form a part hereof, show by way ofillustration, and not of limitation, specific embodiments in which thesubject matter may be practiced. The embodiments illustrated aredescribed in sufficient detail to enable those skilled in the art topractice the teachings disclosed herein. Other embodiments may beutilized and derived therefrom, such that structural and logicalsubstitutions and changes may be made without departing from the scopeof this disclosure. This Detailed Description, therefore, is not to betaken in a limiting sense, and the scope of various embodiments isdefined only by the appended claims, along with the full range ofequivalents to which such claims are entitled.

Thus, although specific embodiments have been illustrated and describedherein, it should be appreciated that any arrangement calculated toachieve the same purpose may be substituted for the specific embodimentsshown. This disclosure is intended to cover any and all adaptations orvariations of various embodiments. Combinations of the aboveembodiments, and other embodiments not specifically described herein,will be apparent to those of skill in the art upon reviewing the abovedescription.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separate embodiment.

1. A method, comprising: sending a selected data type withoutself-definition information to a receiver if a state capable ofinterpreting the selected data type has been maintained by the receiver;and sending the selected data type with the self-definition informationto the receiver if the state capable of interpreting the selected datatype has not been maintained by the receiver.
 2. The method of claim 1,further comprising training the receiver to enter the state capable ofinterpreting the selected data type.
 3. The method of claim 3, furthercomprising determining the state capable of interpreting the selecteddata type has been maintained by the receiver when the receiver isdetermined not to have received a communication from another transmitterafter the receiver has been trained to enter the state capable ofinterpreting the selected data type.
 4. The method of claim 1, furthercomprising determining the state capable of interpreting the selecteddata type has been maintained by the receiver when no transmitter otherthan a training transmitter is capable of communicating with thereceiver.
 5. The method of claim 1, further comprises determining thestate capable of interpreting the selected data type has been maintainedby the receiver when the receiver is operating in accordance with aprotocol that prohibits communication by the receiver with anon-training transmitter until a training transmitter indicates that acommunication session between the training transmitter and the receiveris terminated.
 6. The method of claim 1, further comprising determiningthe state capable of interpreting the selected data type has beenmaintained by the receiver when control of a communications channel usedby the receiver and a training transmitter has not been released by thetraining transmitter.
 7. The method of claim 1, wherein the sending theselected data type further comprises sending the selected data typeusing an Institute of Electrical and Electronics Engineers (IEEE) 802.11protocol.
 8. The method of claim 1, wherein the sending the selecteddata type further comprises sending the selected data type with theself-definition information provided in a packet header.
 9. The methodof claim 1, the sending the selected data type further comprises sendingthe selected data type with the self-definition information indicatingat least one of a multicarrier transmission technique, a modulation, acode rate, a code type, a power, and a beam-forming parameter.
 10. Anarticle comprising a computer readable medium having associatedinstructions, wherein the instructions, when executed, result in amachine performing: sending a selected data type without self-definitioninformation to a receiver if a state capable of interpreting theselected data type has been maintained by the receiver; and sending theselected data type with the self-definition information to the receiverif the state capable of interpreting the selected data type has not beenmaintained by the receiver.
 11. The article of claim 9, furthercomprising determining the state capable of interpreting the selecteddata type has been maintained by the receiver when an access pointdetermines that no information will be communicated to the receiverexcept by the access point.
 12. The article of claim 9, furthercomprising determining the state capable of interpreting the selecteddata type has been maintained by the receiver when control of acommunications channel used by the receiver and a training transmitterhas not been released by the training transmitter.
 13. An apparatus,comprising: a transmitter to selectively send a selected data typewithout self-definition information to a receiver if a state capable ofinterpreting the selected data type has been maintained by the receiverand send the selected data type with the self-definition information tothe receiver if the state capable of interpreting the selected data typehas not been maintained by the receiver.
 14. The apparatus of claim 13,further comprising memory to store the self-definition information. 15.The apparatus of claim 13, wherein the self-definition informationindicates at least one of a multicarrier transmission technique, amodulation, a code rate, a code type, a power, and a beam-formingparameter.
 16. The apparatus of claim 13, wherein the selected data typeis sent to the receiver by the transmitter as a series of frames.
 17. Asystem, comprising: a transmitter to selectively send a selected datatype without self-definition information to a receiver if a statecapable of interpreting the selected data type has been maintained bythe receiver and send the selected data type with the self-definitioninformation to the receiver if the state capable of interpreting theselected data type has not been maintained by the receiver; and areceiver to receive the selected data type.
 18. The system of claim 17,further comprising an omnidirectional antenna capable of being coupledto the receiver.
 19. The system of claim 17, further comprising memoryincluded in the receiver to store an indication of the state.
 20. Thesystem of claim 17, wherein the selected data type is sent to thereceiver by the transmitter as a series of adaptively modulated packets.